Field
Embodiments of the present disclosure generally relate to a plasma enhanced chemical vapor deposition (PECVD) chamber and cleaning methods.
Description of the Related Art
PECVD is generally employed to deposit thin films on substrates, such as organic light emitting diode (OLED) substrates and semiconductor substrates. PECVD is generally accomplished by introducing a precursor gas into a vacuum chamber having a substrate disposed on a substrate support. The precursor gas is typically directed through a gas distribution showerhead situated near the top of the vacuum chamber. The precursor gas in the vacuum chamber is excited into a plasma by applying an RF power to a chamber electrode from one or more RF sources coupled to the chamber. The plasma forms a layer of material on a surface of a substrate that is positioned on a substrate support. The gas distribution showerhead is generally connected to an RF power source and the substrate support is typically connected to the chamber body to create an RF power return path.
The process temperature of PECVD processes varies depending on the types of processes. Some processes, such as thin film encapsulation (TFE), require a low temperature. During a TFE process, the temperature of the substrate support is typically maintained at around 80 degrees Celsius. Other thin film depositions using PECVD may maintain the temperature of the substrate support at over 200 degrees Celsius. A PECVD chamber may have residue from the deposition process collecting on the walls and other surfaces, thus a routine cleaning is needed. A low temperature negatively affects the cleaning rate. Inadequate temperature control in the processing chamber may adversely affect deposition efficiency, gas flow distribution, deposited film profile uniformity and chamber cleanness control.
Thus, an improved method and apparatus is needed to enhance temperature control during a cleaning process and deposition process performed in a PECVD chamber.